Today, the Irish Sunday Mirror can reveal the sick mind behind the callous murder of Garda Tony Golden which shocked and repulsed the nation.

Psychopath Mackin, 24, told pals his gun-making, various arrests and brutal knee-cappings were the stuff of gangster movies.

We can also reveal that after a raid on his home in Omeath, Co Louth , police searched land near his property for buried bombs and an arsenal of weapons earlier this year.

Evil Mackin blasted Gda Golden, 36, and his partner Siobhan Phillips, 22, with a Glock pistol before turning the gun on himself last Sunday.

Brave Siobhan’s family are praying for a miracle as the injuries she suffered have led to fears she may never fully recover.

A former pal of Mackin’s told the Irish Sunday Mirror how the thug got it into his head he was playing the bad guy in a movie.

He said: “He used to always say his life was like a film and he was the bad guy.

“He must genuinely have started believing it and he was scum.

“No one wanted to know him and look at his funeral, barely anyone turned up. If it wasn’t so tragic it would be sad as he badly needed help but his criminal links let him down.

“He was a leper and no one wanted to touch him.

“It just seems to strange that he wasn’t ever jailed.

“He was dangerous and everyone knew it and look what he did in the end.”

Siobhan Phillips (Image: newraypics)

The horrific injuries mum-of-two Siobhan suffered means she will be scarred for life after being blasted up to five times by the deranged gunman – if she survives..

It is understood the hairdresser has lost the sight in one eye and there are serious concerns she may never see again. A family source told the Irish Sunday Mirror: “We are waiting every hour for updates.

“Her life will never be the same again. She’s lost the sight in one of her eyes for definite.

“But the doctors are hoping that if she survives, then she’ll have some sort of quality of life.”

Mackin lived in a world of his own, believing he was a big-time gangster, and his obsession with guns had previously garnered police attention.

Sources have told how he was arrested in Newry around four years ago for having a p.38 handgun but was bailed and nothing ever came of it. The gun nut also videoed himself brandishing the weapon but stupidly filmed a very distinctive tattoo on his wrist and cops were able to arrest him.

Mackin’s criminal careeer was also linked to extortion bids in his native Co Down and he was believed to have been behind a number of knee-cappings.

The thug was secretly cremated at a ceremony in Belfast on Friday.

Mackin regularly physically abused his partner Siobhan and she was preparing to leave him when he launched his horrific attack.

Gda Golden was escorting Ms Phillips to the family home to pick up some possessions when Mackin ambushed the pair. He was well-known to gardai and members of the Special Branch raided his home in January after a tip-off from the FBI.

He had desperately tried to ingratiate himself with dissident elements but republican groups wanted nothing to do with him.

A source said last night that Mackin didn’t care about the repercussions of his actions.

The source added: “He was an absolute lunatic. He is alleged to have carried out beatings and kneecappings for the dissidents.

“He was not a dissident but liked to think of himself as one.

“At the end of the day he was just a thug who liked violence.”

Earlier this week we revealed how Mackin left home when he was just 15 after he attacked his mum and held a gun to her throat. He was caged for attempted murder when he was just a teen after brutally beating another lad.

After his release from Hydebank Young Offenders Centre in Belfast, he ended up homeless.

He appeared in court in July 2012 charged with having sickening images of women having sex with animals and was before the Special Criminal Court in January charged with IRA membership.

Mackin had been on bail ever since but had become increasingly erratic in recent months and was taking cocaine and prescription drugs.

He moved to Omeath in North Louth with Siobhan and their two children, who are both under four, but their relationship was described as volatile.

Gda Golden’s funeral was held earlier this week as thousands paid their last respects to the heroic officer in Blackrock, Co Louth.

His grieving brother Patrick paid an emotional tribute at the service.

He said: “Some words immediately come to mind, such as hero, gentle giant, family man, caring rock and idol.

“These words cannot explain how good a man he was and how much we all love him.